NI-6535 in continues mode.

[Etai Liv]

I wrote this code in order to output a train bits continuously.The code is:

#include <NIDAQmx.h>
#include <ansi_c.h>
#include <cvirte.h>    
#include <userint.h>
#include "test_6535.h"
#include "toolbox.h"

//==============================================================================
// Constants

//==============================================================================
// Types

//==============================================================================
// Static global variables

static int panelHandle;

//==============================================================================
// Static functions

//==============================================================================
// Global variables

//==============================================================================
// Global functions
#define NUM_SAMPLES  100

/// HIFN The main entry-point function.
int main (int argc, char *argv[])
{
float64 adDutyCycle[1], adFreq[1];
int32 iSampleWritten;
uInt8 abArray[NUM_SAMPLES];
TaskHandle gTaskHandle;
int error = 0, i = 0;
unsigned __int64 ui64Samples = NUM_SAMPLES;

 for (i = 0; i < sizeof (abArray); i++)
 {
  if (i % 2)
  {
   abArray[i] = 0;
  }
  else
  {
   abArray[i] = 1;
  }
  
  
 }
 adDutyCycle[0] = 10.;
 adFreq[0] = 1920;
 
 DAQmxCreateTask ("",&gTaskHandle);
 error = DAQmxCreateDOChan (gTaskHandle, "6535/port0/line3", "",
          DAQmx_Val_ChanPerLine);
 
 error = DAQmxSetTimingAttribute (gTaskHandle,
          DAQmx_SampQuant_SampMode,
          DAQmx_Val_ContSamps);

 error = DAQmxSetTimingAttribute (gTaskHandle, DAQmx_SampClk_Rate,
          2500.);
 
 error = DAQmxSetTimingAttribute (gTaskHandle,
          DAQmx_SampQuant_SampPerChan, ui64Samples);
 
 
 error = DAQmxWriteDigitalLines (gTaskHandle, sizeof (abArray), 1,
         10.0, DAQmx_Val_GroupByChannel,
         abArray, &iSampleWritten, 0);
   
 while (1)
 {
  ProcessSystemEvents ();
 }
  
 
    return 0;
}

The program executes DAQmxWriteDigitalLines only once and than stops transmitting.

My question is:

What I need to do in order to transmit the data  continuously?

Best regards

Etai.

[Jake_H]

Are you working from an example program or is this some code you wrote? The function help for ProcessSystemEvents suggests a piece of code (below) to run continuously. 

while (!done)

{

ProcessSystemEvents ();

RunAdditionalStep ();

}

Also, there are some continuous digital examples in the DAQmx folder that should have been installed with the software. Start Menu » National Instruments » NI-DAQ » Text Based Code Support » ANSI C